Pipe-bending machine and method



Sept. 16, 1930. H. E. HARVEY PIPE BENDING MACHINE AND IBTHOD Filed July 30, 1924 3 Sheets-Sheet 1 W nw: N N E W E PM W I 1 Flll a BY WE. SM M ATTORNEYS.

H. E. HARVEY PIPE BENDING MACHINE AND lm'mon Sept. 16, 1930.

s Sheets-Sheet 2 Filed July 30, 1924 JNVENTOR. 5" BY 3 2 A TTORNEYJ.

Sept. 16, 1930. H. E. HARVEY 1,775,750

PIPE SENDING MACHINE AND METHOD v Filed July so, 1924 s Sheets-Sheet s,

A TTORNEYJ.

Qm QM INVENTOR.

a. By fl 7 KMQ M R AW m+ W/ Qmh NT 3 r u mm m* Patented Sept. 16, 1930 UNITED STATES PATENT oFncE HARRY E, HARVEY, F CLEVELAND HEIGHTS, OHIO, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO STEEL AND TUBES, INC., OF GLEVELAND, OHIO, A CORPORATION OF OHIO PIPE-BENDING MACHINE AND METHOD Application filed July 30,

This invention relates to pipe bending machines, and more particularly to the bending dies which form a part thereof. It relates also to a method of bending pipe.

, Preparatory to bending a length of pipe,

it is the present practice toprovide a solid hearing within the portion of the pipe to be bent, to eliminate wrinkling and to preserve the original cross sectional shape of the pipe during the bending operation. The solid bearings now employed for this purpose are usually either a metal mandrel, or a liquid material, such as rosin, which will harden after being poured into the pipe, to be bent. The use of these, and any other types of internal bearings require insertion and removal operations which add very materially to the cost of bent pipe. 1

An object of my invention is toprovide an apparatus in which pipe can be bent without the use ofa filler, or bearing member within thepipe.

Another object of my invention" is to provide a pair of bending dies which cooperate tion of pipe in a lengthwise direction.

Another object of my invention is to provide a pair of cooperating bending dies, one

of which is provided with a plurality of slidable tensioned sections which cooperate separately with the other die to gradually bend a section of pipe in a lengthwise direction therebetween.

Another object of my invention resides in a pipe bending die in which sections thereof are replaceable to provide work engaging faces of various degrees of curvatures.

These and other objects and the invention itself will be set forth in detail hereinafter.

In the accompanying drawings, illustrating embodiments of my invention Fig. 1 is a side elevation of a pipe bending machine with my improved dies assembled therewith;

with the machine;

Fig. 3 is a fragmentary plan view of the dies in the process of bending a pipe;

Fig. 4 is a sectional view of the dies in bending process taken on line 44 of Fig. 3;

so that they gradually engage and bend a sec- Fig. 2 is a plan view of the dies assembled 1924.. Serial No. 729,077.

Fig. 5 is a sectional view of 0m? of the dies taken on line 5-5 of Fig. 3;

Fig. 6 is a plan view of an end section of one of the dies;

Fig.7 is an end elevation of the same;

Fig. 8 is a plan view of a set of dies, one of which is a modification form;

Fig. 9 is a front elevation of the modified form of die, having one of the end sections removed from the base;

Fig. 10 is a plan view of a removable end section of the modified form ofdie;

Fig. 11 is a front elevation of the same;

Fig. 12 is' a side elevation of a portion of one of the movable die members; and

Fig. 13 is a side elevation of a modified form of a movable die member.

Referring to the drawings by characters of reference, 15 represents the bed of a bull dozer machine which is secured to the flooring 16 by bolts 17. A large gear 18 is keyed to a shaft 19 mountedin suitable hearings on the bed, and is driven by a train of gears which are rotated from a source of power,

in any conventional manner. A pair of aligned die operating links 20 are pivotally connected eccentrically to the gear 18, so that as the gear rotates-the links will transmit a reciprocal movement to the die with which they are attached.

A cross head or die base 21 extends across the upper surface of the bull dozer bed and is retained thereupon by angular brackets 22 which engage under the side flanges 23 of the machine bed, the brackets being secured to the die base by bolts 24. With such construction the die base will slide upon the upper surface of the machine bed when reclprocated by the links 20. Wrist pins 25 project from recesses in the sides of the dle. base and the ends of the links 20 are pivotally mounted upon the projecting ends of the wrist pins. The links are retained in such position by caps 26 secured at the outer ends a of the wrist pins by bolts 27 which extend through the caps, bearings and the end wall of the die base, the bolts being so retained by nuts 28.

The die base 21 provides the support of the male pipe engaging die 29 which is shown herein formed as an integral casting. The rear end of such die is secured to the die base 21 by bolts 30, hearing members 31 being provided intermediate the section and the die base through which the bolts also project.

The die base is in the form of a hollow frame,

and the bolts 30 can readily be inserted, or removed, to assemble or remove the pipe cngaging die with the die base. It will be seen that die sections having work engaging faces of different curvatures can be attached to the die base 21. The forward end of the remov able die 29 is curved and is provided with a pipe engaging groove 32 which is curved lengthwise thereof in the shape in which it is desired to bend a pipe.

The female die is positioned upon the machine bed in horizontal alignment with the male die, and the female die is so arranged that its work engaging face cooperates with the work engaging face of the male die, such faces being of similar curvatures at the completion of the bending movement of the male die to provide the final form of the pipe bent therebetween.

The base 33 of an angular bracket is secured by bolts 34 upon the machine bed, and the upstanding flange 35 of such bracket provides a support to which the female die is secured. Spaced ribs 36 are provided intermediate the base and flange to strengthen the bracket intermediate its ends. The base of the female die consists of a pair of vertically spaced and horizontally extending plates 37 which are provided at their outer ends with inwardly extending flanges 38. Stationary die sections 39 are carried between the plates 37 and are secured by bolts 40. The bolts extend through the plates and the stationary die sections and are so secured by nuts 41.

These end sections are each provided with a recess 42 which extends across their top and bottom faces, and the flanges 38 of the plates are adapted to project into such recesses to position the die sections therewith. Apertures 43 are provided in the sections to receive the bolts 40, previously described. Ap-

ertures 44 also extend vertically through the end die sections to receive dowel pins 45 which extend through apertures in the plates 37. It will be seen that the bolts and dowel pins securely maintain the end sections in assembled position with the die base, when the plate flanges extend into the grooves therein, thereby securing the sections against disv alignment in any direction.

Bolts 46 extend through apertures in the bracket flange 35 and are screwed into tapped apertures 90 extending into the rear face of the stationary die sections, thereby securing the female die with the machine base frame.

The front face of the stationary die sections are curved to conform to the bend in the pipe whichis desired, and a groove 91 extends centrally therein, such groove being of sufficient size in cross section to accommodate substantially one-half of pipe which is to be bent. The portions 94 0 such faces are substantially the same curvature as the cooperating portions of the bending face of the male die, and the portions 95 of such faces are straight and provide a support for positioning the pipe prior to the bending operation.

A plurality of removable die sections 47, 48 and 49 are slidably mounted side by side intermediate the stationary end sections 39 of the die. The rear portion of such movable die sections extend intermediate the inner'walls of the die base plates and their forward ends are formed so that they will extend between the flanges 38 of the base plates. The shoulders 92, formed by the difference in the thickness of the forward and rear portions of the movable die sections, provide an abutment which will engage the flanges 38 and limit the outward movement of the movable die sections. The shoulders are so positioned that the outer point of the work engaging face of each movable die section will extend at least in alignment with the outer work engaging portion of the stationary end sections of the die. The movable die sections are provided with shanks 50 which extend through apertures in the bracket flange 35 and an angle iron 53 which is spaced from and parallel with the bracket flange. A pair of studs 51 are screwed into apertures 52 in the bracket flange 35, and the angle iron is retained thereupon by nuts 54 and 55 which are screwed upon the studs on opposite sides thereof. The nuts can be adjusted to regulate the distance the angle iron is spaced from the die. Spring retainers 93 are adjustably secured to the shanks of the movable die sections and coil springs 52 surround the shanks and hear at their ends against the retainers and the angle iron. By adjusting the angle iron lengthwise upon the studs 51, the pressure exerted by all of the springs can be regulated, and by adjustment of the retainers, the tension exerted by each coil spring can be regulated. The tension of the springs is adjusted to normally pro ect the movable die sections to their outermost position.

The outer ends of the movable die sections 47 48-and 49 are curved and form the pipe engaging face of the female die. The curvature of these movable die faces corresponds to that portion of the male die face with which they cooperate, and when moved to their innermost position by the action of the male die, they form a continuous curve with the end faces of the stationary end die section. These faces are provided with a central groove 96 which is in alignment with the groove 91 in the faces of the end sections. at the completion of the pipe bending operation. During the bending operation the pipe will be seated within the grooves in the work-engagtially enclosed thereby.

Raised bosses 56 extend upwardly from the surface of the machine base, and bolts 57 are screwed longitudinally therethrough, so that they will engage with the die supporting bracket. These bolts permit the longitudinal adjustment of the female die upon the machine base, and serve as a support for the bracket, to brace the same against the pressure exerted by the movable die duringthe bending operations.

In Fi s. 8 to 11 inclusive, I have illustrated a modified formflof female die, which functions in the same manner, and is secured to the machine bed in the same way, as the female die previously described. In this modification the die base consists of the same base plates 37 having flanges 38 extending inwardly from the outer end thereof as previously described. Filler blocks 60 of the same length as the stationary end die sections are secured between the plates by the bolts 40 and the dowel pins 45, just as the end sections themselves are in the previously described embodiment of my invention. The edge of the upper and lower surface of the outer end of the filler blocks is recessed at 61 and the outer end of the blocks extends transversely inside of the outer end of the plates 37 ,A key 62 projects from the outer end of each of the filler blocks, and such keys are seated within the recesses 63 in the stationary die sections 64 when assembled. The stationary end die sections 64 are recessed at 65 so that they can abut against the outer endof the filler blocks, between the flanged ends of the base plates, and are assembled in such positionby bolts 97. i The bolts 97 extend through and are countersunk in apertures in the filler blocks and are screwedinto threaded apertures 66 in the stationary end sections. The outer faces of these sections are curved similarly to those previously described, and are grooved to receive a pipe partially therein. This modification differs from the previously described female die, in that the stationary end sections can be attachedland detached without disassembling the die; basesections pipe engaging cooperating faces of the same curvature, a length of pipe is positioned with" in the grooves in the straight end faces of the stationary die sections of the female die and the outermost portions of the movable die section faces. It will be noted that when in normal position the movable sections are .projected beyond the adjacent portion of the stationary sections by the springs 52, and that they are preferably tensioned so that the ends of the groove in the middle movable section aligns with the straight portion of the groove at the outer ends of the stationary sections, and that the outermost end of the grooves adjacent the end sections, in the movable sections on each side of the middle movable section are also in line with the outermost portions of the grooves in end and middle sections. The length of pipe will therefore bear against such points in the grooved faces of the female die section when positioned to be bent. The machine is then operated to move the male die toward the female die, and the length of pipe between the sides of the middle movable diesection 48 will first be bent around the male die as the movement of the male die toward the female die is continued. The section of the pipe, adjacent this bent section, is next bent between the movable die sections 47 and 49 and the male die. The movement of the-male die causesthe movable die sectionsto travel in the same direction therewith against the tension of the springs 52 so that the length of pipe between the movable die sections and the male die will bebent to final form previous to the bending of the adjacent ends. Continued movement of the male die will bend the section of the pipe between the ends of the stationary end section of the female die,

and when the male die has moved to the end of its movement the pipe is bent to the desired curvature, the faces of the movable sections of the female die, when in such position, forming a continuous curve parallel with the adjacent stationary end die sections. In Fig. 3, I have illustrated the position of the pipe and the dies at an intermediate point of the bending operation. It will beseen that the principle which I have incorporated in my dies is to gradually bend a pipe around a die lengthwise of its axis, and that by providing dies and operating themas above set forth, I accomplish the bending without the use of an internal hearing. I

In' Fig. 13 I have illustrated a modified form of movable die section which corresponds to the movable section 49. It will be observed that in this modification the die section is a regular shape and that bearing strips 99 are riveted to the top and bottom faces flanges 38 of the base plates to limit the outward movemeht of the movable sections.

. The grooves in the faces of the die members could be of various shapes in cross section and-I do not limit my invention to the curved cross section illustrated in the drawings. It is also clearly apparent that the relation of the male and female dies could be reversed, so that the female die described Could be operated by the cross head, instead of the male die, to accomplish the same results hereinbefore set forth.

Various changes can be made in other of the details of construction herein described without departing from the spirit of my invention, and the scope of what I claim.

What I claim is 1. In a pipe bending machine, a pair of dies fitted and adapted to cooperate to bend a pipe therebetween, one of said dies comprising a base, curved end sections secured to said base, a plurality of slidable sections carried by said base intermediate said end sections, said end and intermediate sections being formed to provide a curved pipe engaging face, and means exerting pressure against said slidable sections, normally maintaining their faces in advance of the adjacent faces of said end sections.

2. In a pipe bending machine, a pair of dies fitted and adapted to cooperate to bend a pipe therebetween, one of said dies com prising a base, a plurality of slidable sections carried by said base, said sections being formed to provide a continuous curved pipe engaging face, and means exerting pressure against said sections to normally maintain their faces disaligned and advanced from the position in which they form a continuous curve.

3. In a pipe bending machine, a pair of dies fitted and adapted to cooperate to bend a pipe therebetween, one of said dies comprising a base, sections secured to said base, a plurality of separately slidable sections carried by said base intermediate the secured die sections, said sections being formed at one end to provide a continuously curved work engaging bending face. and means exerting pressure against each of said slidable sections individually to normally maintain their faces in advance of the faces of the secured sections.

4. A die for pipe bending machines comprising a base, stationary sections secured to said base, a plurality of separately slidable sections carried by said base intermediate the secured die sections and grooved for a pipe, said sections being formed at one end to provide a continuously curved work engaging bending face, means for exerting pressure against each of said slidable sections to normally maintain their faces in advance of the faces of said secured sections, and means to limit the movement of said slidable sections.

5. A die for pipe bending machines comprising a base, work engaging sections secured to said base, a plurality of separately slidable work engaging sections carried by said base intermediate the secured sections and grooved for a pipe, the ends of said sections being formed to provide a continuously curved and grooved pipe engaging bending face, and separate means for exertlng pressure against each of said slidable sectlons to normally maintain their pipe engaging faces in advance of the faces of said secured sections.

6. A die for pipe bendin machines comprising a base, curved face pipe engaging sections secured to said base, a plurality of.

slidable pipe engaging sections carried by said base intermediate the secured sections, said sections being formed to provide a continuously curved pipe bending and fitting face, a separate coil spring arranged to exert pressure against each of said slidable sections to normallysmaintain their pipe engaging faces in advance of the faces of said secured sections, and means for limiting the movement of said slidable sections.

7. A sectional bending die comprising a base, end sections secured to said base, a plurality of slidable sections carried by said base intermediate the secured sections, one end of said secured and. slidable sections being formed to provide a continuously curved pipe bending and fitting face, a coil spring exerting pressure against each of said slidable sections to normally maintain. their pipe engaging faces in advance of the faces of said secured die sections, and means for regulating the pressure exerted by each spring. 7

8. A sectional bending die comprising a base, grooved pipe engaging sections secured to said base, a plurality of slidable pipe engaging sections carried by said base mtermediate said secured sections, and coil springs exerting pressure against said slidable sections, the ends of said secured and slidable die sections removed from said base being formed to provide a continuous curved bending face when the slidable sections are pressed inwardly relative to-said base, said springs normally projecting the curved faces ofsald slidable sections outwardly from the curved v faces of said'secured sections.

9. A die for pipe bending machines comprising a base, a plurality of pipe engaging sections slidably carried by and projecting from said base, and coil springs for exerting pressure against said sections, the ends of said sections removed from said base bein formed to provide a continuously curved an grooved pipe engaging face when in a position adjacent said base, said springs normally projecting the slidable sections outwardly from said base with their faces disaligned.

10. A sectional bending die for pipe bending machines comprising a base, pipe engaging sections secured to said base, a plurality of slidable pipe engaging sections carried by and projecting from said base intermediate said secured sections, and coil springs exerting pressure against said slidable sections, the ends of said secured and slidable die sections removed from said base being formed to provide a continuously curving pipe fitting bending face when the slidable sections are in their innermost position, said springs normally maintalmng the faces of. said slidable sections at varying distances in advance of the faces of the secured sections.

11. .A. sectional bending die for pipe bending machines comprising a base, pipe fitting and engaging sections secured to said base, a plurality of slidable pipe engaging sections carried by said base intermediate said secured sections, and coil springs exerting pressure against said slidable sections, the ends of said secured and slidable sections removed from said base being formed to provide a continuously curved bending face when said slidable sections are in their inner position relative tothe base, said slidable sections being limited in their movement and being arranged so that their pipe engaging faces are disaligned by the pressure of said springs.

12. A sectional bendin die comprising a base, three separate slidable sections carried by said base intermediate two secured sections, and coil springs for exerting varying pressures against said slidable sections, the ends of said secured and slidable sections beingformed to provide a continuously curved bending and pipe fitting face when pressed toward the base, said springs normally maintaining the faces of said slidable sections in disa'lignment, the face of the middle slidable section projecting the greatest distance from the base. V

13. In a pipe bending machine, a stationary die, and a reciprocating die adapted to cotinuous curved face, the faces of said sectional die cooperating with the face of the other die to gradually bend a pipe lengthwise of its axis around the face of the other die.

14. A sectional bending die comprising a base, sections secured to said base, a plurality of separately slidable sections carried by said base intermediate the secured sections, said secured and slidable sections being formed at one end to provide a continuously curved work engaging bending and pipe fitting face, and means exerting pressure against said slidable sections normally maintaining their faces in advance of'the faces of the secured sections, said slidable sections being removable from said base.

15. A sectional bending die for bending pipe comprising a base, and end sections secured to said base, a plurality of separately slidable sections carried by said base intermediate the end sections, said end and slidable sections being formed at one end to provide a continuousl curved work engagrigidly therewith, said section having a curved pipe engaging and fitting face, the other of said dies comprising a base, end sections removably secured to said base, slidable intermediate sections removably mounted with said base, said sections having pipe engaging faces adapted to provide a curved bending face complementary to the bending face of the other die, and springs for normally maintaining said slidable die sections at different positions forwardly of the position in which the faces are complementary to the faces of the other die.

17. A die for pipe bending machines comprising a base,.a plurality of slidable Work 5 engaging section's carried by said base, said sections having pi e engaging and fitting faces adapted to orm a continuous curve when pressedtoward said base, springs exerting pressure against said sections to nor-- mo mally project the faces thereof away from said base, and means to limit the outward movement of said sections, said means being arranged to permit the faces of the middle section to project beyond the faces of the sections on each side thereof.

18. In a pipe bending machine, the combination of a base, a rain on said base and'a cushion anvil, both ram and anvil being fitted to engage a pipe to be bent, and means to no close the ram'and anvil together to complete the formation of the curve in thepipe.

19. The method of bending pipe which consists of gripping the pipe at the portion which it is desired shall be the crest of a fin- 1 ished bend, bending the pipe where gripped, and then completely an successively bending adjoining increments thereof away from the gripped portion while maintaining the on the previously bent portions of pipe to prevent deformation of the previously bent portions.

21. The method of bending pipe which comprises tightly gripping and slightly bending the empty pipe midway between the ends of the part to be bent, then bendin the pipe adjoining the gripped portion an progressively away therefrom until the desired bend is obtained while maintaining the grip on the previously bent ortions of pipe to prevent deformatmn of t e previously bent portions.

22, In a pipe bending machine, a pair of dies adapted to cooperate to bend a pipe therebetween, one of said dies comprising a base, end die sections movably carried by said'base, a slidable die section carried by said base disposed intermediate said end sections, said intermediate section being formed to provide a curved pipe engaging face, and means exerting pressure against said slidable section normally maintaining its face in advance of the adjacent faces of said other sections.

23. In a pipe bending machine, a pair of dies adapted to cooperate to bend a pipe therebetween, one of said dies comprising a base, die sections movably carried by said base, a slidable die section carried by said base intermediate the said die sections, yieldable means to normally maintain the slidable section with its face in advance of the adjoining faces of the said die sections, said die sections being adapted to cooperate with the movable die section to form a female die.

24. The method of bending pipe which comprises bending a predetermined localized area of the pi e, and then simultaneously completely ben ing a longitudinal increment of t e pipe adjoining each side of the bent area.

In testimony whereof I hereunto afiix my signature this 23rd day of HARRY July, 1924. E. HARVEY. 

